JP2015175777A - Refiner of radioisotope, and refining method of radioisotope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refiner of radioisotope and a refining method of radioisotope which are capable of improving refining efficiency of radioisotope.SOLUTION: A refiner 1 of radioisotope according to embodiment comprises a piping 6 as a solution pressure-feeding part which pressure-feeds solution in a bubbling collection part 3 to a connection pipe 4. In the case of collecting radioisotope in the bubbling collection part 3, radioisotope vaporized in a heating part 2 flows from the connection pipe 4 toward the bubbling collection part 3. On the other hand, the piping 6 pressure-feeds the solution from the bubbling collection part 3 toward the connection pipe 4. Specifically, the piping 6 can flow the solution backward in an opposite direction to the flow of vaporized radioisotope. A pipe wall of the connection pipe 4 can be easily cleaned without failing to be washed by making the solution to flow backward to the connection pipe 4.

Description

  The present invention relates to a radioisotope purification apparatus and a radioisotope purification method.

  For example, a radioisotope (RI) used in a PET examination (positron tomography examination) or the like in a hospital or the like can be obtained by purifying a substance containing a radioisotope with a purification apparatus. Such a purification apparatus is disclosed in Patent Document 1. In the purification apparatus shown in Patent Document 1, a radioisotope is adsorbed from a mixture by a column, and the radioisotope adsorbed by the column is dissolved in a solution and recovered.

JP2013-13821A

  Here, as a radioactive isotope purification device, the radioactive isotope is collected by heating and vaporizing the vaporizable radioactive isotope and bubbling the gas containing the vaporized radioactive isotope in the solution. There is. In the connecting pipe between the heating unit and the bubbling collection unit, the gas may be cooled on the front side of the bubbling collection unit. As a result, there is a problem that the radioisotope in the gas is deposited on the pipe wall of the connecting pipe, and the purification efficiency is lowered. In addition, although a method of washing and collecting the deposited radioisotope by flowing a solution in the gas flow path is also conceivable, it is difficult to wash the entire wall surface of the connecting pipe, and the portion that fails to flow May occur. In addition, from the viewpoint of preventing exposure, it is difficult for the operator to manually flow the solution into the connecting pipe.

  The present invention has been made to solve the above-described problems, and provides a radioisotope purification apparatus and a radioisotope purification method capable of improving the purification efficiency of the radioisotope. With the goal.

  The apparatus for purifying a radioisotope according to the present invention heats a substance containing a radioisotope, thereby vaporizing the radioisotope, and bubbling the vaporized radioisotope in a solution, thereby A bubbling collection unit that collects elements, a heating unit and a bubbling collection unit are connected, and a connection pipe that can supply vaporized radioisotopes to the bubbling collection unit, and a solution pipe in the bubbling collection unit A solution pumping unit that pumps the solution to the head.

  The apparatus for purifying radioactive isotopes according to the present invention includes a solution pumping unit that pumps the solution in the bubbling collection unit to the connecting pipe. When collecting the radioisotope in the bubbling collection part, the radioactive same element vaporized in the heating part flows from the connecting pipe toward the bubbling collection part. On the other hand, the solution pumping unit pumps the solution from the bubbling collection unit toward the connecting pipe. That is, the solution pumping unit can reversely flow the solution in the direction opposite to the flow of the vaporized radioisotope. In this way, by allowing the solution to flow backward to the connecting pipe, the pipe wall of the connecting pipe can be washed easily and without losing flow. Therefore, the backflowed solution can efficiently recover the radioisotope remaining on the wall of the connecting pipe. As described above, the purification efficiency of the radioisotope can be improved.

  In the radioisotope purification apparatus according to the present invention, the solution pumping unit may pump the solution by supplying a gas to the bubbling collection unit. As a result, the amount of the solution used for backflow to the connecting pipe can be reduced.

  In the radioisotope purification device according to the present invention, the bubbling collection unit may be provided with a discharge port for discharging gas to the outside and a valve capable of opening and closing the discharge port. If gas or a solution is supplied to the bubbling collection part in the state which closed the discharge port with the valve, the pressure in the bubbling collection part will rise and the solution will be pumped to the connecting pipe. This makes it possible to pump the solution to the connecting pipe with a simple configuration.

  The method for purifying a radioisotope according to the present invention comprises a heating step of vaporizing a radioisotope by heating a substance containing the radioisotope in a heating section, and a solution of the vaporized radioisotope in a bubbling collection section. The bubbling collection step for collecting the radioisotope by bubbling with, the recovery step for collecting the solution in which the radioisotope is bubbled in the bubbling collection step, and the solution supplied in the bubbling collection section, A solution pumping step of pumping to a connecting pipe connecting the heating unit and the bubbling collecting unit.

  According to the method for purifying a radioisotope according to the present invention, it is possible to obtain the same actions and effects as those of the above-mentioned radioisotope purification apparatus.

  According to the present invention, the purification efficiency of radioisotopes can be improved.

FIG. 1 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 3 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 4 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 5 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 6 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 7 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to an embodiment of the present invention. FIG. 8 is a conceptual diagram showing a configuration of a radioisotope purification apparatus according to a modification.

  Hereinafter, a radioisotope purification apparatus according to the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  First, the outline | summary of the refiner | purifier which concerns on one Embodiment of this invention is demonstrated using FIG. As shown in FIG. 1, the purification apparatus 1 is an apparatus that purifies a radioisotope from a substance containing a radioisotope. The purified radioisotope is used for the production of radiopharmaceuticals (including radiopharmaceuticals) that are radioisotope-labeled compounds (RI compounds) used for PET examinations (positron emission tomography examinations) in hospitals and the like. The purification device 1 includes a heating unit 2, a bubbling collection unit 3, a connection pipe 4, and a pipe 6. In the present embodiment, a solid target W irradiated with a charged particle beam generated by an accelerator is illustrated as a substance to be purified (a substance containing a radioisotope).

  The heating unit 2 has a function of vaporizing the radioisotope by heating the solid target W. The heating unit 2 can heat the solid target W disposed therein to about 200 to 700 ° C., and the radioisotope formed on the solid target W evaporates to indicate gas (indicated by R in FIG. 1). It becomes. In addition, iodine, bromine, etc. are mentioned as a radioisotope which can be vaporized by the heating of the heating part 2. FIG. The heating unit 2 includes an installation unit 7 in which the solid target W is installed, and a lead-out pipe 8 that guides the radioisotope vaporized in the installation unit 7 to the outside of the heating unit 2. When the heating unit 2 starts heating, the solid target W after the charged particle beam is irradiated on the installation unit 7 is installed. The heating unit 2 operates the heater to raise the temperature in the installation unit 7 and vaporize the radioisotope. The heating unit 2 supplies the carrier gas (for example, nitrogen and oxygen) to the installation unit 7 and the outlet tube 8 while heating, thereby leading the vaporized radioisotope from the outlet tube 8 to the outside of the heating unit 2.

  The bubbling collection unit 3 has a function of collecting the radioisotope by bubbling the vaporized radioisotope in the solution. The bubbling collection unit 3 includes a storage unit 11 that stores a solution for collecting a radioisotope, a bubbling unit 12 that introduces a gas containing a radioisotope into the solution in the storage unit 11 and performs bubbling. And a discharge port 14 for discharging the gas in the section 11. The storage part 11 is a tubular container extending in the vertical direction. However, the shape of the storage part 11 is not particularly limited as long as the solution can be stored. The bubbling unit 12 is configured by a pipe that is introduced from the upper end of the storage unit 11 into the storage unit 11 and extends toward the bottom of the storage unit 11. The lower end portion of the bubbling portion 12 is spaced apart from the bottom portion of the storage portion 11 and is open. In a state where the solution is stored in the storage unit 11, the lower end of the bubbling unit 12 is immersed in the solution. Thereby, the gas introduced from the upper end side of the bubbling part 12 is ejected from the lower end part of the bubbling part 12, and is supplied as a bubble in the solution. The solution may be any solution as long as it can collect the radioisotope from bubbles, and an aqueous sodium hydroxide solution, distilled water, or the like is employed. In addition, the connection part between the outer peripheral surface of the bubbling part 12 and the upper end part of the storage part 11 is sealed without a gap. The discharge port 14 is configured by a pipe connected in the vicinity of the upper end of the storage unit 11. Note that one end of the discharge port 14 is connected to the storage unit 11 and the other end is connected to a gas recovery unit (not shown). A valve that can open and close the outlet 14 is provided at the other end of the outlet 14 (see FIG. 5).

  The connecting pipe 4 is a pipe that connects the heating unit 2 and the bubbling collection unit 3 and can supply the vaporized radioisotope to the bubbling collection unit 3. Since the connecting pipe 4 is provided outside the heating unit 2, the connecting tube 4 is a portion where heating by the heater of the heating unit 2 is not performed. In this embodiment, the connecting pipe 4 includes a horizontal portion 4A that extends horizontally from the side end of the heating unit 2, a bent portion 4B that bends at a right angle, and a vertical portion 4C that extends vertically downward from the bent portion 4B. , It is comprised by the piping which has. Note that one end of the horizontal portion 4A of the connecting pipe 4 is connected to the outlet pipe 8 of the heating unit 2. The lower end portion of the vertical portion 4 </ b> C of the connection pipe 4 is connected to the upper end portion of the bubbling portion 12. The lower end portion of the vertical portion 4 </ b> C of the connecting pipe 4 is formed to have a smaller diameter than other portions of the connecting pipe 4 in accordance with the diameter of the bubbling portion 12.

  The pipe 6 has a function as a solution pumping unit that pumps the solution in the bubbling collection unit 3 to the connection pipe 4. The pipe 6 pressure-feeds the solution to the connection pipe 4 by supplying gas to the bubbling collection unit 3. The gas supplied at this time is an inert gas, and for example, nitrogen, helium or the like is employed. In the present embodiment, the pipe 6 also functions as a solution supply unit that supplies a solution to the storage unit 11 of the bubbling collection unit 3. The pipe 6 supplies the solution to the storage unit 11 of the bubbling collection unit 3 with the discharge port 14 closed by a valve 18 (see FIG. 5), thereby connecting the solution in the bubbling collection unit 3 to the connecting pipe. 4 can be pumped. The pipe 6 also functions as a solution recovery unit that recovers the solution in the storage unit 11. The pipe 6 is connected to the lower end of the storage part 11. A part of one end side of the pipe 6 extends downward from the lower end of the storage part 11. Further, the other end of the pipe 6 is connected to a pump (not shown) for supplying a gas, etc., and connected to a pump (not shown) for supplying a solution, etc., to a recovery unit (not shown) for recovering the solution. It is connected. A pipe for supplying the solution and collecting the solution may be provided separately from the pipe 6 for supplying the gas. Moreover, the piping which supplies a solution, and the piping which collect | recovers a solution may be comprised by separate piping.

  Next, a purification method using the radioisotope purification apparatus 1 according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 2, the purification apparatus 1 supplies the solution SL <b> 1 to the storage unit 11 of the bubbling collection unit 3 using a pipe 6. As a result, the solution SL1 is stored in the storage unit 11. Next, the purification apparatus 1 vaporizes the radioisotope by heating the solid target containing the radioisotope with the heating unit 2 (heating process). The purification apparatus 1 transfers the radioisotope vaporized by the carrier gas G1 to the bubbling collection unit 3 through the connection pipe 4. The vaporized radioisotope is supplied into the solution SL1 from the lower end portion of the bubbling portion 12 together with the carrier gas G1. The radioactive isotope floats in the solution SL1 as bubbles and dissolves into the solution SL1. The gas G2 that has not been dissolved in the solution SL1 is discharged from the discharge port 14. Thereby, the refinement | purification apparatus 1 collects a radioisotope by bubbling the vaporized radioisotope in solution SL1 of the bubbling collection part 3 (bubbling collection process). After the completion of the bubbling collection process, as shown in FIG. 3, the purification apparatus 1 collects the solution SL1 in which the radioisotope is bubbled in the bubbling collection process (collection process). Specifically, the solution SL1 is transferred to an external collection unit via the pipe 6.

  As shown in FIG. 4, the purification apparatus 1 supplies the cleaning solution SL <b> 2 to the storage unit 11 of the bubbling collection unit 3 using the pipe 6. As a result, the solution SL2 is stored in the storage unit 11. Moreover, the refiner | purifier 1 bubbles gas G3 in solution SL2 by supplying gas G3 from the connection pipe 4 side (storage part washing | cleaning process). As a result, the tube wall in the vicinity of the lower end of the reservoir 11 (the region indicated by the thick line in FIG. 4) is washed, and the radioisotope remaining on the tube wall is removed.

  Next, as shown in FIG. 5, the purifier 1 closes the outlet 14 with a valve 18. In this state, the purification apparatus 1 additionally supplies the solution SL2 to the storage unit 11 of the bubbling collection unit 3 using the pipe 6. Due to the pressure balance, the solution SL2 flows backward in the piping constituting the bubbling portion 12, and the liquid level of the solution SL2 rises. Thereby, the refiner | purifier 1 can pump solution SL2 to the upper end part (it may also reach a part of lower end part of the connection pipe 4) of the piping which comprises the bubbling part 12 (1st solution pumping). Process). As a result, the tube wall of the bubbling portion 12 (the region indicated by the thick line in FIG. 5) is washed, and the radioisotope remaining on the tube wall is removed.

  Next, as shown in FIG. 6, the purifier 1 supplies the inert gas G <b> 5 to the storage unit 11 of the bubbling collection unit 3 using the pipe 6. The inert gas G5 is stored in a region on the outer peripheral side of the bubbling unit 12 of the storage unit 11, and the pressure of the solution SL2 flows backward in the piping that configures the bubbling unit 12, and the liquid level of the solution SL2 rises and is connected. The vertical part 4C of the tube 4 is reached. Thereby, the refiner | purifier 1 can pump solution SL2 to the vertical part 4C of the connection pipe 4 (2nd solution pumping process). Moreover, the refinement | purification apparatus 1 supplies the inert gas G5 further, and the inert gas G5 rises as a bubble in the piping which comprises the bubbling part 12. FIG. Thereby, bubbling is performed in the vertical portion 4 </ b> C of the connecting pipe 4. As a result, the tube wall of the vertical portion 4C of the connecting tube 4 (the region indicated by the thick line in FIG. 6) is washed, and the radioisotope remaining on the tube wall is removed. When the solution SL2 is pumped to the connecting pipe 4, the liquid level of the solution SL2 stops at the midway position of the vertical portion 4C or before the horizontal portion 4A so that the solution SL2 does not go to the heating portion 2 side. Adjustment is made so as not to reach part 4A. As described above, after cleaning the connecting pipe 4, as shown in FIG. 7, the purification apparatus 1 recovers the solution SL2 containing the remaining radioisotope (recovery step). Specifically, the solution SL2 is transferred to an external recovery unit via the pipe 6.

  Next, operations and effects of the radioisotope purification apparatus 1 and the radioisotope purification method according to the present embodiment will be described.

  In the connecting pipe 4 between the heating unit 2 and the bubbling collection unit 3 of the purification apparatus 1, the carrier gas is cooled on the front side of the bubbling collection unit 3. As a result, the radioisotope in the carrier gas is deposited on the tube wall of the connection tube 4. Here, as a method of recovering the radioisotope remaining on the tube wall of the connection pipe 4, the remaining radioisotope is obtained by flowing a solution toward the tube wall of the connection pipe 4 (for example, from the upper side or the side). The method of washing | cleaning and collect | recovering is mentioned. As an example, the supply part which supplies a solution to the bending part 4B of the connection pipe 4 is provided, and the structure which performs washing | cleaning by sending a solution to the pipe wall of the vertical part 4C by flowing a solution from the said supply part is mentioned. . However, in such a method, it is difficult to transmit the solution evenly over the entire circumference of the tube wall of the vertical portion 4C of the connection tube 4, and there is a possibility that a portion that fails to flow is generated. When a supply unit that does not lose its flow is employed, there is a problem that the structure of the supply unit becomes complicated. In addition, from the viewpoint of preventing exposure, it is difficult for the operator to manually flow the solution into the connecting pipe.

  On the other hand, the radioisotope purification apparatus 1 according to the embodiment includes a pipe 6 that pumps the solution in the bubbling collection unit 3 to the connection pipe 4. When the radioisotope is collected by the bubbling collection unit 3, the radioactive same element vaporized by the heating unit 2 flows from the connection pipe 4 toward the bubbling collection unit 3. In contrast, the pipe 6 pumps the solution from the bubbling collection unit 3 toward the connection pipe 4. That is, the pipe 6 can reversely flow the solution in the direction opposite to the flow of the vaporized radioisotope. In this way, by allowing the solution to flow backward to the connecting pipe 4, the pipe wall of the connecting pipe 4 can be washed easily and without loss of flow. Specifically, when the liquid level of the backflowed solution rises to the vicinity of the vertical portion 4C of the connecting pipe 4, the entire region below the liquid level in the connecting pipe 4 is immersed in the solution. It becomes. Therefore, the backflowed solution can efficiently recover the radioisotope remaining on the tube wall of the connecting tube 4. As described above, the purification efficiency of the radioisotope can be improved. In addition, according to the radioisotope purification method according to the present embodiment, the same operations and effects as those of the above-described radioisotope purification apparatus 1 can be obtained.

  In the radioisotope purification apparatus 1 according to this embodiment, the pipe 6 pumps the solution by supplying gas to the bubbling collection unit 3. As a result, the amount of the solution used when flowing back to the connecting pipe 4 can be reduced.

  In the radioisotope purification apparatus 1 according to the present embodiment, the bubbling collection unit 3 is provided with a discharge port 14 for discharging gas to the outside and a valve 18 that can open and close the discharge port 14. Yes. If gas or a solution is supplied to the bubbling collection part 3 in the state which closed the discharge port 14 with the valve 18, the pressure in the storage part 11 of the bubbling collection part 3 will rise, and a solution will be pumped to the connection pipe 4. FIG. This makes it possible to pump the solution to the connecting pipe 4 with a simple configuration.

  The present invention is not limited to the embodiment described above.

  For example, the configuration of the bubbling collection unit is not limited to the configuration as shown in the above-described embodiment, and any configuration can be adopted as long as the radioisotope can be collected by bubbling. May be. For example, as shown in FIG. 8, a vial 21 may be employed as the bubbling collection unit 23. A tube 24 connected to a heating unit (not shown) is connected to the vial 21. The radioisotope vaporized in the heating unit is collected by bubbling in the solution stored in the vial 21 from the tip of the tube 24. The tube 24 functions as a connecting tube that connects the heating unit and the bubbling collection unit 3. Here, a supply pipe 25 is connected to the vial 21. The supply pipe 25 can supply the inert gas G <b> 6 into the vial 21. As a result, the solution in the vial 21 can be backflowed through the tube 24. At this time, the supply pipe 25 can function as a solution pumping unit.

  DESCRIPTION OF SYMBOLS 1 ... Purification apparatus, 2 ... Heating part, 3 ... Bubbling collection part, 4 ... Connection pipe, 6 ... Pipe (solution pumping part), 14 ... Discharge port.

Claims (4)

A heating unit for vaporizing the radioisotope by heating a substance containing the radioisotope; and
Bubbling collection unit for collecting the radioisotope by bubbling the vaporized radioisotope in a solution;
A connecting pipe that connects the heating unit and the bubbling collection unit, and is capable of supplying the vaporized radioisotope to the bubbling collection unit;
A radioisotope purification apparatus, comprising: a solution pumping unit that pumps the solution in the bubbling collection unit to the connection pipe.   The radioisotope purification device according to claim 1, wherein the solution pumping unit pumps the solution by supplying a gas to the bubbling collection unit.   The radioisotope refining device according to claim 1 or 2, wherein the bubbling collection unit is provided with a discharge port for discharging gas to the outside and a valve capable of opening and closing the discharge port. A heating step of vaporizing the radioisotope by heating a substance containing the radioisotope in a heating unit;
Bubbling collection step of collecting the radioisotope by bubbling the vaporized radioisotope in a solution of a bubbling collection section;
A recovery step of recovering the solution in which the radioisotope is bubbled in the bubbling collection step;
A method of purifying a radioisotope, comprising: a solution pumping step of pumping the solution supplied into the bubbling collection unit to a connection pipe connecting the heating unit and the bubbling collection unit.